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A novel, rapid and efficient route to imidazo[1,2-a]pyridines under ambient, aqueous and metal-free conditions is reported. The NaOH-promoted cycloisomerisations of N-propargylpyridiniums give quantitative yield in a few minutes (10 g scale). A comparison of common green metrics to current routes showed clear improvements, with at least a one order of magnitude increase in space-time-yield.

Direct C-3 arylation of imidazo[1,2-a]pyridines with aryl tosylates and mesylates has been accomplished by employing palladium(II) acetate associated with SPhos (2-dicyclohexylphosphino-2′,6′-dimethoxybiphenyl) or L1 (2-(2-(diisopropylphosphino)phenyl)-1-methyl-1H-indole). This catalyst system can be applied to a wide range of aryl sulfonates and shows excellent C-3 regioselectivity of imidazo[1,2-a]pyridine. These results represent the first examples of using tosylate- and mesylate-functionalized arenes as the electrophile partners for this regioselective direct arylation.

The reaction of allyl palladium(II) chloride dimer and 4,4′-bis(RfCH2OCH2)-2,2′-bpy, 1a–b, in the presence of AgOTf resulted in the synthesis of cationic palladium complex, [Pd(η3-allyl)(4,4′-bis-(RfCH2OCH2)-2,2′-bpy)](OTf), 2a–b where Rf = C9F19 (a), C10F21 (b), respectively. The reaction of [PdCl2(CH3CN)] or K2PdCl4 with 1b, gave rise to the synthesis of [PdCl2(4,4′-bis-(C10F21CH2OCH2)-2,2′-bpy)], 3b. The quantitatively determined solubility curves of 2a–b and 3b in DMF indicated dramatic increase of solubility for 2a–b and 3b from −40 to 90 °C. The catalyst-recoverable Pd-catalyzed Heck/Sonogashira reactions were successfully achieved in DMF with microwave-assistance. The cationic Pd-catalyzed Heck arylation of methyl acrylate was selected to demonstrate the feasibility of recycling 2a–b using DMF as a solvent under microwave-assisted thermomorphic conditions. At the end of each cycle, the product mixtures were cooled, and then the catalysts were recovered by decantation. The Heck arylation catalyzed by 2b under microwave-assisted mode exhibited good recycling results favoring the trans product. To our knowledge, this is the first example of cationic Pd-catalyzed Heck arylation under microwave-assisted thermomorphic conditions. Additionally, recoverable 3b-catalyzed Sonogashira reactions were also achieved successfully in DMF. The reactions under microwave-assistance gave much better results in yield and in efficiency than that under conventional thermal heating.

Various benzimidazoles (26 examples) are obtained by a simple, convenient, and environmentally benign synthesis from ortho-phenylenediamines and aldehydes via aerobic oxidation in wet organic solvents.

Kesterite Cu2ZnSnS4 nanoparticles, wurtzite Cu2ZnSnS4 nanoparticles, as well as Cu2ZnSnS4 particles with a mixture of both structures are prepared by hot injection of the sulfur source into an oleylamine (OA) solution of Cu(OAc)2, ZnCl2, and SnCl4 using elemental sulfur, 1-dodecanethiol, and thioacetamide in OA as sulfur source, respectively (235 °C, 1 h).

The nucleoside antibiotic constituent, herbicidin K (I), is isolated along with three known nucleoside antibiotic constituents, herbicidin A,B,F from Streptomyces scopuliridis RB72.

The transition from a fossil fuel-based economy to a bio-based economy necessitates the exploitation of synergies, scientific innovations and breakthroughs, and step changes in the infrastructure of chemical industry. Sustainable production of chemicals and biopolymers should be dependent entirely on renewable carbon. White biotechnology could provide the necessary tools for the evolution of microbial bioconversion into a key unit operation in future biorefineries. Waste and by-product streams from existing industrial sectors (e.g., food industry, pulp and paper industry, biodiesel and bioethanol production) could be used as renewable resources for both biorefinery development and production of nutrient-complete fermentation feedstocks. This review focuses on the potential of utilizing waste and by-product streams from current industrial activities for the production of chemicals and biopolymers via microbial bioconversion. The first part of this review presents the current status and prospects on fermentative production of important platform chemicals (i.e., selected C2-C6 metabolic products and single cell oil) and biopolymers (i.e., polyhydroxyalkanoates and bacterial cellulose). In the second part, the qualitative and quantitative characteristics of waste and by-product streams from existing industrial sectors are presented. In the third part, the techno-economic aspects of bioconversion processes are critically reviewed. Four case studies showing the potential of case-specific waste and by-product streams for the production of succinic acid and polyhydroxyalkanoates are presented. It is evident that fermentative production of chemicals and biopolymers via refining of waste and by-product streams is a highly important research area with significant prospects for industrial applications.

A highly efficient head-to-tail dimerization of a styrene was developed using a cationic palladium(II)-catalyzed selective CC bond forming reaction. The complex [AllylPd(PPh3)]+OTf−, which is believed to generate ‘palladium hydride’ (PdH), catalyzed the dimerization of various styrenes in excellent yields as single isomers. This Pd(II)-catalyzed reaction provides a new economical CC bond forming method.

Novel type III-B dendrimers are synthesized via a modified copper-catalyzed alkyne—azide cycloaddition, a Glaser—Hay′s acetylenic oxidative homocoupling, and an amide formation.

(amides) 1 and 2, respectively, as shown in Scheme 1. 7 Addition of glycosides to 1 or 2 in CDCl3 caused downfield shifts of the NH resonances of the hosts, indicating the formation of intermolecular hydrogen bonds between the NH's of the host and OH's of sugars. Analysis of the 1 H NMR titration data gives the binding constants listed in Table 1. The striking characteristic of 1 and 2 is their highly diastereoselective recognition of glycosides (entry 3 vs. 1, 2, 4) combined with moderate anomer-selective recognition of glucopyranosides (entry 1 vs. 2). 1 and 2 show higher affinity for both α -D-mannopyranoside and D-glucopyranosides than for β-D-galactopyranoside. The stereochemical arrangement of OH groups on C-3, C-4 and C-5 of Glc is the

Cleyeratannin A (I*a), B (I*b), C (II*) are isolated along with two known compounds from the leaves of Cleyera japonica (CJ).

Carbon coated title composite cathodes for lithium ion batteries are mechanochemically prepared from mixtures of Mn2V2O7, Li2CO3, (NH4)2PO4, and sucrose, followed by firing at 800 °C for 10 h in a flowing 5% H2/Ar gas stream.

The electronic effects of the aldehyde substituents as well as the nature of the secondary amine are found to affect reaction rate and yield.

The reaction is carried out in a Pd-coated tubular reactor placed in line with copper tubing in a continuous flow platform.

Two new alkylphenol derivatives, ardisiphenol E (Ia) and F (Ib), are isolated along with the known ardisiphenol D.

A novel and efficient method for the conversion of carboxylic acids to primary amides using N,N′-carbonyldiimidazole in combination with ammonium acetate/triethyl amine system in [BMIM]BF4 is developed.

Here we review the equatorial β-directing effects of electron-withdrawing protecting groups at remote positions of mannopyranosyl donors, mannuronate donors, rhamnopyranosyl donors, and 2,6-dideoxyglucopyranosyl donors. We discuss the equatorial α-directing effect of an electron-withdrawing group at the N-5 position of sialyl donors. The proposed mechanism and origin of some of the equatorial β-directing effects are described. We also review the effects of potentially participating, electron-withdrawing protecting groups at remote positions of glycopyranosyl and glycofuranosyl donors on the glycosylation stereochemistries. Further, we present substantial evidence in favor of the remote participation by the electron-withdrawing protecting groups and also include reports that are opposed to remote participation.

Enzymatic synthesis of oligosaccharides has traditionally employed glycosyltransferases, or glycosidases run in transglycosylation mode. Glycosynthases, mutant glycosidases in which the catalytic nucleophile has been removed, function as efficient transferases with glycosyl fluoride donors, frequently giving stoicheometric yields. Glycoligases, in which the acid/base catalyst has been mutated, synthesise sulfur-linked oligosaccharides when an activated donor is used in conjunction with a thiosugar acceptor, or in some cases O-glycosides. Recent results in the engineering and evolution of these two classes of mutant enzymes along with “classical” glycosyltransferases using a variety of screening methodologies, including robot-assisted ELISA assays and FACS cell sorting, are discussed.

Effects of potentially participating groups at remote positions of glycopyranosyl and glycofuranosyl donors on the glycosylation stereochemistry are reviewed. Substantial evidences in favor of the remote participation by protecting groups are presented and also included are a few reports opposed to the remote participation.

Simple and efficient N-arylation of carbazoles is achieved in LiCl-mediated, CuI-catalyzed reactions with aryl iodides or bromides.

N-Arylation of carbazole has been achieved in high yields within 1 h using a microwave-assisted catalytic CuI reaction with no organic ligand. The N-arylation can be performed by various arylhalides, such as phenyl, pyridine, thiophene, and thiazole moieties. Specifically, N-arylated bromocarbazoles were converted into useful synthetic intermediates for functionalized carbazole materials.

Blue fluorescent materials based on 9,9'-diethyl-2-diphenylaminofluorene derivatives were synthesized and characterized. These materials were used as the blue dopant materials for the emitting layer of organic lightemitting diode devices with the following device structure: ITO/DNTPD (40 nm)/NPB (20 nm)/MADN: dopants (2%, 20 nm)/Alq3 (40 nm)/Liq (1.0 nm)/Al. All devices exhibited highly efficient blue emission. One of these devices exhibited a maximum luminance, luminous efficiency, power efficiency and CIE x, y coordinates of 8400 cd/m 2 , 8.10 cd/A at 20 mA/cm 2 , 3.36 lm/W at 20 mA/cm 2 and (0.151, 0.159), respectively. A deep blue device with CIE coordinates of (0.152, 0.139) showed the maximum luminance, luminous efficiency and power efficiency of 8630 cd/m 2 , 6.31 cd/A at 20mA/cm 2 and 2.62 lm/W at 20 mA/cm 2 , respectively.

Single-walled carbon nanotubes (SWNTs) are used as supporting materials for palladium (Pd) nanoparticles generated in situ in ionic liquid (IL); Pd nanocatalysts on SWNTs exhibit superior reactivity for hydrogenation of aryl ketones in IL under mild conditions (1 atm of H 2 (g) and room temperature) and can be reused above 10 times without any loss of catalytic activity.

However, all of these methods invariably suffered from one or more drawbacks such as harsh reaction conditions, long reaction times, difficulty of manipulation, use of exotic reagents, and low reaction yields. Furthermore, in the most of known methods for demethylation of aryl methyl ethers, use of large excess amounts of demethylating agents have been generally required. Thus, it is highly desirable to develop an improved convenient and efficient procedure for demethylation reactions of aryl methyl ethers.Magnesium iodide etherate, MgI

An efficient and direct one-pot glycosylation method using anomeric hydroxy sugars as glycosyl donors, employing 3-fluorophthalic anhydride and triflic anhydride as activating agents, has been developed. The present glycosylation utilizing 3-fluorophthalic anhydride resulted in few to no undesired self-condensed esters than the glycosylation using phthalic anhydride. Intermediates in the present glycosylation were identified by an NMR study.

Bioactive natural products often possess uniquely functionalized structures with unusual modes of action; however, the natural product itself is not always the active species. We discuss molecules that draw on protecting group chemistry or else require activation to unmask reactive centers, illustrating that nature is not only a source of complex structures but also a guide for elegant chemical transformations which provides ingenious chemical solutions for drug delivery.

Two red fluorescent DCJTB derivatives (Red 1 and 2) based on modified pyrans were synthesized and their electroluminescent properties were investigated. Multilayered OLEDs were fabricated with the device structure of ITO/ NPB (40 nm)/Red 1, 2 or DCJTB (0.5 or 1%): Alq3 (20 nm)/Alq3 (40 nm)/Liq (2 nm)/Al. All devices exhibited efficient red emissions. In particular, a device containing emitter Red 2 as a dopant in the emitting layer, the maximum luminance was 8737 cd/m 2 at 12.0 V, the luminous and power efficiencies were 2.31 cd/A and 1.25 lm/W at 20 mA/cm 2 , respectively. The peak wavelength of the electroluminescence was 638 nm with the CIE (x,y) coordinates of (0.63, 0.36) at 7.0 V.

The chiral binaphthyl based carboxaldehyde HPBC promotes the stereoselective decarboxylation of aminomalonic acid derivative (I).

The reaction of allyl silyl ethers with triaryl phosphites affords functionalized trisubstituted olefins.

[Pd(allyl)]BF4 (I), [Pd(allyl)(2,4-hexadiene)]BF4 (II), and [Pd(MeCN)4](BF4)2 (III) catalyze the dehydrogenation of NH3BH3 most efficiently with a release of 2.0 equiv.

Chiral binaphthol-based receptors (I) are prepared for the use in enantioselective recognition of 1,2-amino alcohols and for the conversion of L-amino acids to D-amino acids.

New compounds related to miltirone and diazepam containing a halogen substituent in ring B or a heterocyclic nitrogen atom in ring A have been synthesized.

The surface-enhanced Raman scattering of phenylacetylene was investigated in a silver sol and at a silver electrode. Phenylacetylene was found to adsorb on the silver surfaces as phenylacetylide after losing its acetylenic proton. Phenylacetylide appeared to assume more or less perpendicular stance with respect to the silver surface, with the adsorption occurring mainly via σ donation from the electron rich alkynyl carbon to the metal. At least two different kinds of site seemed to be present on the silver surface. In one kind phenylacetylide adsorbed so strongly that other anionic species could not replace it, while competitive adsorption was possible in the other kind. The appearance of triplet bands in the CC triple bond region was rationalized in terms of two kinds of surface sites and a Fermi resonance interaction between the ν(CC) fundamental and the (ν 1 + ν 13 ) combination modes.

Several benzenesulfonyl and arylmethanesulfonyl chlorides 2 are synthesized in excellent yields by the aqueous chlorination of aryl (or benzyl) methoxymethyl sulfides 1. Functionalized sulfides 1 d-g can be prepared easily from bromophenyl methoxymethyl sulfides 1 b,c

Surface-enhanced Raman scattering of 4-aminobenzonitrile has been investigated in a silver sol and at a silver electrode. The molecule was found to adsorb on the silver surface via both the amino and nitrile groups, with the benzene ring lying flat with respect to the surface. The most important interaction between the nitrile group and the surface was found to occur via π coordination. The observations made in this work are entirely consistent with the previously proposed model that most conjugated aromatic nitriles adsorb on silver via the CN π system, and that their ν CN frequencies can either decrease or increase depending on the relative importance of nitrile-to-metal π donation and conjugation breakup due to side-on coordination.

Spectral shifts of ν(CN) bands occurring when aromatic nitriles adsorb on silver surfaces have been investigated by surface-enhanced Raman scattering (SERS). Attention has been focused on the SERS of 1,4-dicyanobenzene(1,4-DCB) and 4-cyanobenzoic acid (4-CBA), both of which possess two functional groups available for bonding, to establish spectral correlation with the adsorption mechanism. Even though the coordination in most metal—nitrile complexes involes the σ donation of the nitrogen lone-pair electrons, it is found that a majority of aromatic nitriles adsorb on the silver surface via their CN π systems. A slight increase in the CN stretching frequency upon surface adsorption, observable for conjugated aromatic nitriles, is attributed to the disruption of conjugation rather than to end-on coordination.

Diazodecomposition of N-(tert-butyl)-N-(3-buten-1-yl)diazoacetamides catalyzed by dirhodium(II) tetrakis[methyl 2-pyrrolidone-5(S)-carboxylate], Rh2(5S-MEPY)4, and tetrakis[methyl 2-oxazolidinone-4(S)-carboxylate], Rh2(4S-MEOX)4, forms products from intramolecular cyclopropanation in good yields with enantiomeric excesses ranging from 60–90%. Intramolecular cyclopropanation with N, N-diallyldiazoacetamide (72% ee) is competitive with intramolecular [3+2] dipolar cycloaddition.

Reactive sputtering has been used to prepare the lead Chevrel phase PbMo{sub 6}S{sub 8} on several substrates. The effect of processing parameters such as H{sub 2}S flow rate, Pb sputtering current, substrate temperature, and annealing temperature were found to be very important in determining sample purity. Formation of PbMo{sub 6}S{sub 8} from an as-deposited material apparently occurred at significantly lower annealing temperatures (400-800{degrees}C), compared to conventional solid-state preparations (1000{degrees}C). The thin films of PbMo{sub 6}S{sub 8} were active thiophene hydrodesulfurization catalysts: the absence of impurities including MoS{sub 2} could be confirmed for these materials, before and after reaction. Because the characteristic catalytic properties of the lead Chevrel phases were observed, reactive sputtering may be applicable for the preparation of other Chevrel phases on catalyst supports. 54 refs., 11 figs., 4 tabs.

The two stereoisomers 12 and 16 of l, 4-dimethyl-l, 4-diazepan-2-one, a central feature of liposidomycins, have been synthesized starting from L-ascorbic acid and sarcosine.

C -Alkylation of 1,4,5-trihydroxyanthraquinone with nitroalkanes in alkali gives regioselective 3-substitution contrary to literature; this is applied to a two-step synthesis of the anthracyclinone 9 .